EntityQ575152· pop 9· linked from 166 articlesPoppySign in to saveelectronic survelance sateliteConnectionssignals intelligenceEntityOrionEntityUnited StatesCountrySoviet UnionConceptphotographyEntityammoniaEntityWayback MachineEntityNational Security AgencyEntityEdward Mills PurcellEntitygeostationary orbitEntitylow Earth orbitEntityDijkstra's algorithmEntitygeosynchronous orbitEntityVandenberg Space Force BaseEntityreconnaissance satelliteEntityradio frequencyEntityInternational DesignatorEntityEdwin H. LandEntitysynthetic aperture radarEntityTodendorfEntityCategories1962 in spaceflight1963 in spaceflight1971 in spaceflightMilitary equipment introduced in the 1960sNational Reconnaissance OfficeNational Reconnaissance Office satellites